apewer-dotnet/Apewer/DateTimeUtility.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace Apewer
{

    /// <summary>System.DateTime 实用工具。</summary>
    public class DateTimeUtility
    {

        #region Private Methods

        private static DateTime GetOrigin()
        {
            return new DateTime(1970, 1, 1, 0, 0, 0, 0);
        }

        private static string FormatDate(DateTime datetime, bool lucid)
        {
            var sb = new StringBuilder();

            var y = NumberUtility.RestrictValue(datetime.Year, 0, 9999);
            var m = NumberUtility.RestrictValue(datetime.Month, 1, 12);
            var d = NumberUtility.RestrictValue(datetime.Day, 1, GetDays(y, m));

            if (y < 10) sb.Append("000");
            else if (y < 100) sb.Append("00");
            else if (y < 1000) sb.Append("0");
            sb.Append(y.ToString());

            if (lucid) sb.Append("-");

            if (m < 10) sb.Append("0");
            sb.Append(m.ToString());

            if (lucid) sb.Append("-");

            if (d < 10) sb.Append("0");
            sb.Append(d.ToString());

            var date = sb.ToString();
            return date;
        }

        private static string FormatTime(DateTime datetime, bool lucid, bool seconds, bool milliseconds)
        {
            var sb = new StringBuilder();

            var h = NumberUtility.RestrictValue(datetime.Hour, 0, 23);
            var m = NumberUtility.RestrictValue(datetime.Minute, 0, 59);
            var s = NumberUtility.RestrictValue(datetime.Second, 0, 59);
            var ms = NumberUtility.RestrictValue(datetime.Millisecond, 0, 999);

            if (h < 10) sb.Append("0");
            sb.Append(h.ToString());

            if (lucid) sb.Append(":");

            if (m < 10) sb.Append("0");
            sb.Append(m.ToString());

            if (seconds)
            {
                if (lucid) sb.Append(":");

                if (s < 10) sb.Append("0");
                sb.Append(s.ToString());

                if (milliseconds)
                {
                    if (lucid) sb.Append(".");
                    if (ms < 10) sb.Append("00");
                    else if (ms < 100) sb.Append("0");
                    sb.Append(ms.ToString());
                }
            }

            var time = sb.ToString();
            return time;
        }

        #endregion

        #region Public Properties

        /// <summary>获取当前本地时间的易读格式文本。</summary>
        public static string NowLucid { get { return ToLucid(DateTime.Now); } }

        /// <summary>获取当前 UTC 的易读格式文本。</summary>
        public static string NowUtcLucid { get { return ToLucid(DateTime.UtcNow); } }

        /// <summary>获取当前本地时间的毫秒时间戳。</summary>
        public static long NowStamp { get { return GetStamp(DateTime.Now); } }

        /// <summary>获取当前 UTC 的毫秒时间戳。</summary>
        public static long NowUtcStamp { get { return GetStamp(DateTime.UtcNow); } }

        /// <summary>获取 1970-01-01 00:00:00.000 的时间对象。</summary>
        public static DateTime Origin { get { return GetOrigin(); } }

        #endregion

        #region Public Methods

        /// <summary>获取安全的 DateTime 对象。</summary>
        public static DateTime GetDateTime(DateTime datetime)
        {
            var origin = GetOrigin();
            var span = datetime - origin;
            var stemp = span.TotalMilliseconds;
            var safely = origin.AddMilliseconds(stemp);
            return safely;
        }

        /// <summary>获取安全的 DateTime 对象。</summary>
        public static DateTime ToDateTime(DateTime datetime)
        {
            return GetDateTime(datetime);
        }

        /// <summary>从毫秒时间戳获取 DateTime 对象。发生异常且不允许异常时将返回 1970-01-01 00:00:00.000。</summary>
        /// <exception cref="System.ArgumentOutOfRangeException"></exception>
        public static DateTime GetDateTime(long stamp, bool exceptable = true)
        {
            var origin = GetOrigin();
            try
            {
                var datetime = origin.AddMilliseconds(Convert.ToDouble(stamp));
                return datetime;
            }
            catch
            {
                if (exceptable) throw new ArgumentOutOfRangeException();
                return origin;
            }
        }

        /// <summary>从毫秒时间戳获取 DateTime 对象。发生异常且不允许异常时将返回 1970-01-01 00:00:00.000。</summary>
        /// <exception cref="System.ArgumentOutOfRangeException"></exception>
        public static DateTime ToDateTime(long stamp, bool exceptable = true)
        {
            var origin = GetOrigin();
            try
            {
                var datetime = origin.AddMilliseconds(Convert.ToDouble(stamp));
                return datetime;
            }
            catch
            {
                if (exceptable) throw new ArgumentOutOfRangeException();
                return origin;
            }
        }

        /// <summary>获取毫秒时间戳。</summary>
        public static long GetStamp(DateTime datetime)
        {
            var origin = GetOrigin();
            var span = datetime - origin;
            var milliseconds = span.TotalMilliseconds;
            var result = Convert.ToInt64(milliseconds);
            return result;
        }

        /// <summary>获取毫秒时间戳。</summary>
        public static long ToStamp(DateTime datetime)
        {
            return GetStamp(datetime);
        }

        /// <summary>判断是否为闰年。</summary>
        public static bool IsLeapYear(int year)
        {
            if (year % 400 == 0) return true;
            if (year % 100 == 0) return false;
            if (year % 4 == 0) return true;
            return false;
        }

        /// <summary>获取指定月份中的天数。</summary>
        public static int GetDays(int year, int month)
        {
            switch (month)
            {
                case 1: case 3: case 5: case 7: case 8: case 10: case 12: return 31;
                case 4: case 6: case 9: case 11: return 30;
                case 2: return IsLeapYear(year) ? 29 : 28;
                default: return 0;
            }
        }

        /// <summary>转换 DateTime 对象到易于阅读的文本。</summary>
        public static string ToLucid(DateTime datetime, bool date = true, bool time = true, bool seconds = true, bool milliseconds = true)
        {
            var safely = GetDateTime(datetime);
            var sb = new StringBuilder();
            if (date) sb.Append(FormatDate(safely, true));
            if (time)
            {
                if (date) sb.Append(" ");
                sb.Append(FormatTime(safely, true, seconds, milliseconds));
            }
            var lucid = sb.ToString();
            return lucid;
        }

        /// <summary>转换 DateTime 对象到易于阅读的文本。</summary>
        public static string GetLucid(DateTime datetime, bool date = true, bool time = true, bool seconds = true, bool milliseconds = true)
        {
            return GetLucid(datetime, date, time, seconds, milliseconds);
        }

        /// <summary>转换 DateTime 对象到紧凑的文本。</summary>
        public static string ToCompact(DateTime datetime, bool date = true, bool time = true, bool seconds = true, bool milliseconds = true)
        {
            var safely = GetDateTime(datetime);
            var sb = new StringBuilder();
            if (date) sb.Append(FormatDate(safely, false));
            if (time)
            {
                // if (date) sb.Append(" ");
                sb.Append(FormatTime(safely, false, seconds, milliseconds));
            }
            var lucid = sb.ToString();
            return lucid;
        }

        /// <summary>转换 DateTime 对象到紧凑的文本。</summary>
        public static string GetCompact(DateTime datetime, bool date = true, bool time = true, bool seconds = true, bool milliseconds = true)
        {
            return ToCompact(datetime, date, time, seconds, milliseconds);
        }

        /// <summary>解析 Lucid 文本。</summary>
        public static Nullable<DateTime> ParseLucid(string lucid)
        {
            var failed = new Nullable<DateTime>();
            if (lucid.IsEmpty()) return failed;

            int year = 0, month = 0, day = 0, hour = 0, minute = 0, second = 0, milli = 0;

            if (lucid.Length < 10) return failed;
            if (lucid[4] != '-' || lucid[7] != '-') return failed;
            year = TextUtility.GetInt32(lucid.Substring(0, 4));
            month = TextUtility.GetInt32(lucid.Substring(5, 2));
            day = TextUtility.GetInt32(lucid.Substring(8, 2));
            if (year < 1) return failed;
            if (month < 1 || month > 12) return failed;
            if (day < 1 || day > DateTime.DaysInMonth(year, month)) return failed;

            if (lucid.Length >= 16)
            {
                if (lucid[10] != ' ' || lucid[13] != ':') return failed;
                hour = TextUtility.GetInt32(lucid.Substring(11, 2));
                minute = TextUtility.GetInt32(lucid.Substring(14, 2));
                if (hour < 0 || hour > 23) return failed;
                if (minute < 0 || minute > 59) return failed;

                if (lucid.Length >= 19)
                {
                    if (lucid[16] != ':') return failed;
                    second = TextUtility.GetInt32(lucid.Substring(17, 2));
                    if (second < 0 || second > 59) return failed;

                    if (lucid.Length >= 23)
                    {
                        if (lucid[19] != '.') return failed;
                        milli = TextUtility.GetInt32(lucid.Substring(20, 3));
                        if (milli < 0 || milli > 999) return failed;
                    }
                }
            }

            var entity = new DateTime(year, month, day, hour, minute, second, milli);
            return new Nullable<DateTime>(entity);
        }

        #endregion

    }

}